Default generated xcodeprojs to gnu++17

PiperOrigin-RevId: 269822463
diff --git a/src/TulsiGenerator/TulsiOptionSet.swift b/src/TulsiGenerator/TulsiOptionSet.swift
index f931b9d..abe4768 100644
--- a/src/TulsiGenerator/TulsiOptionSet.swift
+++ b/src/TulsiGenerator/TulsiOptionSet.swift
@@ -336,7 +336,7 @@
     // List matches the available options for the 'C++ Language Dialect' setting in XCode 10.2.1 and 11.
     // Currently compiler default is equivalent to GNU++98 (Xcode 10.2.1 and 11)
     let cppLanguageStandards = ["compiler-default", "c++98", "gnu++98", "c++11", "gnu++11", "c++14", "gnu++14", "c++17", "gnu++17"]
-    addStringEnumOption(.CLANG_CXX_LANGUAGE_STANDARD, .BuildSetting, "c++11",  cppLanguageStandards)
+    addStringEnumOption(.CLANG_CXX_LANGUAGE_STANDARD, .BuildSetting, "gnu++17",  cppLanguageStandards)
 
     addStringOption(.PreBuildPhaseRunScript, [.TargetSpecializable])
     addStringOption(.PostBuildPhaseRunScript, [.TargetSpecializable])
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/ComplexSingleProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/ComplexSingleProject.xcodeproj/project.pbxproj
index 8b4a78f..8f2d4f7 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/ComplexSingleProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/ComplexSingleProject.xcodeproj/project.pbxproj
@@ -963,7 +963,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -1067,7 +1067,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -1249,7 +1249,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -1446,7 +1446,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSProject.xcodeproj/project.pbxproj
index c77207d..996ca36 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSProject.xcodeproj/project.pbxproj
@@ -409,7 +409,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -525,7 +525,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -624,7 +624,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -723,7 +723,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSTestsProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSTestsProject.xcodeproj/project.pbxproj
index 7f6dc90..1abb0d7 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSTestsProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MacOSTestsProject.xcodeproj/project.pbxproj
@@ -648,7 +648,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -771,7 +771,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -893,7 +893,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -1039,7 +1039,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MultiExtensionProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MultiExtensionProject.xcodeproj/project.pbxproj
index 3e219de..4d936f9 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MultiExtensionProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/MultiExtensionProject.xcodeproj/project.pbxproj
@@ -289,7 +289,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -405,7 +405,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -492,7 +492,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -579,7 +579,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleCCProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleCCProject.xcodeproj/project.pbxproj
index 982f080..7b5e699 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleCCProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleCCProject.xcodeproj/project.pbxproj
@@ -270,7 +270,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -335,7 +335,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -410,7 +410,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -485,7 +485,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleProject.xcodeproj/project.pbxproj
index 393de44..5653295 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SimpleProject.xcodeproj/project.pbxproj
@@ -582,7 +582,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -685,7 +685,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -802,7 +802,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -935,7 +935,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SkylarkBundlingProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SkylarkBundlingProject.xcodeproj/project.pbxproj
index 38dc3fb..9192de7 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SkylarkBundlingProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SkylarkBundlingProject.xcodeproj/project.pbxproj
@@ -303,7 +303,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -394,7 +394,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -477,7 +477,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -560,7 +560,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SwiftProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SwiftProject.xcodeproj/project.pbxproj
index 8166ed8..3ca6530 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SwiftProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/SwiftProject.xcodeproj/project.pbxproj
@@ -345,7 +345,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -412,7 +412,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -508,7 +508,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -604,7 +604,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteExplicitXCTestsProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteExplicitXCTestsProject.xcodeproj/project.pbxproj
index 00ac823..7566838 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteExplicitXCTestsProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteExplicitXCTestsProject.xcodeproj/project.pbxproj
@@ -706,7 +706,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -850,7 +850,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -993,7 +993,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -1168,7 +1168,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteLocalTaggedTestsProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteLocalTaggedTestsProject.xcodeproj/project.pbxproj
index 6304a9a..8668ade 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteLocalTaggedTestsProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteLocalTaggedTestsProject.xcodeproj/project.pbxproj
@@ -389,7 +389,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -467,7 +467,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -552,7 +552,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -653,7 +653,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteRecursiveTestSuiteProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteRecursiveTestSuiteProject.xcodeproj/project.pbxproj
index ef7147c..b979bd6 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteRecursiveTestSuiteProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/TestSuiteRecursiveTestSuiteProject.xcodeproj/project.pbxproj
@@ -611,7 +611,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -729,7 +729,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -854,7 +854,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -1011,7 +1011,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/WatchProject.xcodeproj/project.pbxproj b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/WatchProject.xcodeproj/project.pbxproj
index 0845260..23f6857 100644
--- a/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/WatchProject.xcodeproj/project.pbxproj
+++ b/src/TulsiGeneratorIntegrationTests/Resources/GoldenProjects/WatchProject.xcodeproj/project.pbxproj
@@ -430,7 +430,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -546,7 +546,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -657,7 +657,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
@@ -768,7 +768,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				CLANG_CXX_LANGUAGE_STANDARD = "c++11";
+				CLANG_CXX_LANGUAGE_STANDARD = "gnu++17";
 				CLANG_ENABLE_OBJC_ARC = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
diff --git a/src/TulsiGeneratorTests/PBXTargetGeneratorTests.swift b/src/TulsiGeneratorTests/PBXTargetGeneratorTests.swift
index e7abdce..4a55869 100644
--- a/src/TulsiGeneratorTests/PBXTargetGeneratorTests.swift
+++ b/src/TulsiGeneratorTests/PBXTargetGeneratorTests.swift
@@ -243,7 +243,7 @@
 
     let topLevelBuildSettings = [
       "ALWAYS_SEARCH_USER_PATHS": "NO",
-      "CLANG_CXX_LANGUAGE_STANDARD": "c++11",
+      "CLANG_CXX_LANGUAGE_STANDARD": "gnu++17",
       "CLANG_ENABLE_OBJC_ARC": "YES",
       "CLANG_WARN_BOOL_CONVERSION": "YES",
       "CLANG_WARN_CONSTANT_CONVERSION": "YES",
@@ -299,7 +299,7 @@
 
     let topLevelBuildSettings = [
       "ALWAYS_SEARCH_USER_PATHS": "NO",
-      "CLANG_CXX_LANGUAGE_STANDARD": "c++11",
+      "CLANG_CXX_LANGUAGE_STANDARD": "gnu++17",
       "CLANG_ENABLE_OBJC_ARC": "YES",
       "CLANG_WARN_BOOL_CONVERSION": "YES",
       "CLANG_WARN_CONSTANT_CONVERSION": "YES",